The invention provides nucleotide sequences, which code for the zwa1 gene and processes for the fermentative preparation of amino acids, in particular L-lysine, using coryneform bacteria in which the zwa1 gene is amplified. All references cited herein are expressly incorporated by reference. Incorporation by reference is also designated by the term xe2x80x9cI.B.R.xe2x80x9d following any citation.
Amino acids, in particular L-lysine, are used in human medicine and in the pharmaceuticals industry, but in particular in animal nutrition. It is known that amino acids are prepared by fermentation from strains of coryneform bacteria, in particular Corynebacterium glutamicum. Because of their great importance, work is constantly being undertaken to improve the preparation processes. Improvements to the processes can relate to fermentation measures, such as e. g. stirring and supply of oxygen, or the composition of the nutrient media, such as e. g. the sugar concentration during the fermentation, or the working up to the product form by e. g. ion exchange chromatography, or the intrinsic output properties of the microorganism itself.
Methods of mutagenesis, selection and mutant selection are used to improve the output properties of these microorganisms. Strains which are resistant to antimetabolites, such as e.g. the lysine analogue S-(2-aminoethyl)-cysteine, or are auxotrophic for metabolites of regulatory importance and produce L-amino acids are obtained in this manner.
Recombinant DNA techniques have also been employed for some years for improving the strain of Corynebacterium strains which produce amino acids, by amplifying individual amino acid biosynthesis genes and investigating the effect on the amino acid production.
Review articles in this context are to be found, inter alia, in Kinoshita (xe2x80x9cGlutamic Acid Bacteriaxe2x80x9d, in: Biology of Industrial Microorganisms, Demain and Solomon (Eds.) I.B.R., Benjamin Cummings, London, UK, 1985, 115-142), Hilliger (BioTec 2, 40-44 (1991)) I.B.R., Eggeling (Amino Acids 6:261-272 (1994)) I.B.R., Jetten and Sinskey (Critical Reviews in Biotechnology 15, 73-103 (1995)) I.B.R. and Sahm et al. (Annuals of the New York Academy of Science 782, 25-39 (1996)) I.B.R.
An object of the invention is to provide new measures for improved fermentative preparation of amino acids, in particular L-lysine. Amino acids, in particular L-lysine, are used in human medicine, in the pharmaceuticals industry and in particular in animal nutrition. There is therefore a general interest in providing new improved processes for the preparation of amino acids, in particular L-lysine. When L-lysine or lysine are mentioned in the following, not only the base but also the salts, such as e. g. lysine monohydrochloride or lysine sulfate, are also meant by this.
The new DNA sequence of C. glutamicum which codes for the zwa1 gene and which as a constituent of the present invention is SEQ ID NO 1 and related sequences. The amino acid sequence of the corresponding gene product of the zwa1 gene has furthermore been derived from the present DNA sequence. The resulting amino acid sequence of the zwa1 gene product is SEQ ID NO 2 and related sequences.